Britain must take every possible step to "cut out the terrorist cancer" that exists in the Arabian Peninsula, David Cameron has told MPs.

The Prime Minister warned that the threat from the region, particularly Yemen, had increased and it was in the interests of the world to "come together to deal with this".

He praised the work of the police and intelligence agencies whose efforts had prevented terrorists from "killing and maiming many innocent people whether here or elsewhere".

Speaking to MPs in the Commons following the discovery at the weekend of two bombs in cargo planes in Dubai and at East Midlands Airport, Mr Cameron said: "Clearly the whole country has been focused this weekend on the terrorist threat.

"I want to put on record my thanks, and the thanks of everyone in this House, for all those involved in the international police and intelligence operation, whose efforts clearly prevented the terrorists from killing and maiming many innocent people whether here or elsewhere in the world.

"While we are rightly engaged in Afghanistan to deny the terrorists there, the threat from the Arabian Peninsula, and from Yemen in particular, has grown. So as well as the immediate steps which the Home Secretary will outline, it's clear that we must take every possible step to work with our partners in the Arab world to cut out the terrorist cancer that lurks in the Arabian Peninsula."

Flights containing unaccompanied freight from Somalia will also be suspended in the wake of the cargo plane terror plot, Home Secretary Theresa May said.

The suspension, which will come into force from midnight, is a "precautionary measure" based on "possible contact between al Qaida in Yemen and terrorist groups in Somalia, as well as concern about airport security in Mogadishu", Mrs May told MPs.

Toner cartridges larger than 500g (17.6oz) will also be banned from hand baggage on flights departing from the UK and also on cargo flights unless they originate from a regular shipper with security arrangements approved by the Department for Transport, she said.

Meanwhile German officials have revealed that the two bombs at the centre of the cargo plane terror plot contained 300 grams and 400 grams of explosive PETN, German officials have said. A controlled explosion carried out last year for CNN by UK explosives expert Sidney Alford found that just six grams of PETN punched a large circular dent into a metal plate twice the thickness of an aircraft fuselage.